x/exp/cmd/gorelease: avoid using -mod=mod and support lazy module loading

Details:

- Replaces `go list -mod=mod` with `go list -mod=readonly`.
- Switches to `go get -d` to download dependencies rather than relying on `go
  list` doing so.
- Missing go.sum/go.mod data is now an error.

This CL will be followed by a CL that ensures the filepath.Walk stops at
submodules, and a test asserting that. I figured it'd be good to do separately
since this CL is getting to be hefty. Give a shout if you prefer otherwise!

Updates golang/go#41456

Change-Id: I66f12fe0325e4fed432d8b10c1fe977068e4a030
Reviewed-on: https://go-review.googlesource.com/c/exp/+/263178
Run-TryBot: Jean de Klerk <deklerk@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Trust: Jean de Klerk <deklerk@google.com>
8 files changed
tree: 2a7ee4d2e201006b88781b6c8b8c6a7aeb5e0a2c
  1. .gitattributes
  2. .gitignore
  3. AUTHORS
  4. CONTRIBUTING.md
  5. CONTRIBUTORS
  6. LICENSE
  7. PATENTS
  8. README.md
  9. apidiff/
  10. cmd/
  11. codereview.cfg
  12. ebnf/
  13. ebnflint/
  14. errors/
  15. fsnotify/
  16. go.mod
  17. go.sum
  18. inotify/
  19. io/
  20. mmap/
  21. rand/
  22. shiny/
  23. shootout/
  24. sumdb/
  25. utf8string/
  26. winfsnotify/
README.md

exp

PkgGoDev

This subrepository holds experimental and deprecated (in the old directory) packages.

The idea for this subrepository originated as the pkg/exp directory of the main repository, but its presence there made it unavailable to users of the binary downloads of the Go installation. The subrepository has therefore been created to make it possible to go get these packages.

Warning: Packages here are experimental and unreliable. Some may one day be promoted to the main repository or other subrepository, or they may be modified arbitrarily or even disappear altogether.

In short, code in this subrepository is not subject to the Go 1 compatibility promise. (No subrepo is, but the promise is even more likely to be violated by go.exp than the others.)

Caveat emptor.